The spatial-temporal differences in coupling relationship between urbanization and eco-environment-a case study of the urban agglomeration in the middle reaches of the Yangtze River

Exploring the coupling coordinated relationship between urbanization and eco-environment of the urban agglomeration in the middle reaches of the Yangtze River (UAMRYR) from 2000 to 2015 can provide a theoretical basis for the overall planning and healthy development of the region. Therefore, in this article, we took 31 cities of the UAMRYR as the research area, and established an evaluation system to calculate the urbanization level and eco-environmental quality. Then, using entropy method and coupling measurement model, we analyzed the coupling coordination relationship between urbanization level and eco-environmental quality from spatial and temporal perspectives. Temporally, the coupling degree (CD) and coupling coordinated degree (CCD) continually rose during the 16 years. Spatially, the coordinated development level of urbanization level and eco-environmental quality had significant spatial differences. The CD presented the “northwest-southeast” spatial characteristics corresponding to high-low distribution. The CCD showed an inverted Y-shaped spatial pattern that gradually decreases outward from the provincial capital city. The coordinated development level of urbanization and eco-environment in the UAMRYR showed a central-periphery spatial pattern, and had an obvious spatial variation